Jason Patric Wins Appeal in Custody Battle

Mike Coppola/Getty Images for York Sisters, LLC(LOS ANGELES) -- Jason Patric has won an appeal in Los Angeles in his fight to be recognized as the father of a 4-year-old boy, Gus -- allowing the Lost Boys actor to take his case back to trial after losing an earlier round in court.

Patric biologically fathered the boy with his former girlfriend, Danielle Schreiber. They conceived the child via in-vitro fertilization, or IVF, and co-parented for more than a year before their relationship ended.

Because Patric donated his sperm, an earlier court decision found he was a sperm donor and had no parental rights.

In addition, Patric never signed a birth certificate, Schreiber said.

In a statement to ABC News prior to Wednesday's decision, Schreiber said Patric offered to donate sperm after the two broke up "under the express condition" that it be kept secret and "that he would not be a father to or have any obligations, rights or responsibilities for my child."

A judge in the earlier case agreed, barring Patric from seeing Gus.

But Patric said he's been a dad from Day One. His ammunition included forms he signed at the sperm clinic promising "an intent to parent."